AT&T MERLIN LEGEND Installation & Maintenance Manual page 149

Installation
Connect Lines to the Terminal Block (TB1)
The terminal block (TB1) on the back of the chassis is the
connecting point for T1 service lines and for fault and loopback
wires. Also, if a local power supply is used, the TB1 is the
termination spot for the power supply wires.
WARNING:
Voltages as high as 260 V can occur between the transmit
and receive pairs of the T1 line.
Follow these steps to connect the lines to TB1 on the back of the
CSU chassis (see Figure 27):
1. Connect the T1 service lines to terminals 1 through 5.
2. Connect the fault pair (if provided by the local telephone
company) to terminals 8 and 9.
Connect the DC loopback pair (if provided by the local
3.
telephone company) to terminals 11 and 12.
If the CSU is to be locally powered, connect the power supply
4.
leads to terminals 14 and 15.
Insert the Signal Monitor Unit
After setting the option switches, plug the SMU into the right side
of the 551 T1 L1 CSU chassis.
The SMU has six LEDs and six bantam jacks (see Figure 25).
Tables 3-23 and 3-24 show the functions of the LEDs and the
test jacks on the front panel.
Channel Service Unit 3-41